Roller rock bit



March 22, 1938. A, C. ATLAND 2,111,752

yROLLER ROCK BIT I Filed July 6, 1936 2 Sheets-Sheet l March 22, 1938.

Filed July 6, 1936 2 Sheets-Sheet 2 i to, .dicated by line df-l on Fig. 1..

Patented Mar. 22, 1938 ROLLER ROCK BIT Alfred C. Catland, Alhambra, Calif., assignor to Globe Oil Tools Company, Los Nietos, Calif., a corporation of California Applicationy July 6, 1936, Serial No. 88,989

1?. Claims.

This invention relates to a well drilling tool t and relates more particularly to a roller rock bit for use in the rotary method of well drilling. A

general object of thisinvention is 4to provide a practical, improved and particularly effective roller rock bit.

Another object of this invention is to provide a roller rock bit embodying a novel and simplified arrangement of parts which promotes the general eiliciency of the tool and makes it inexpensive and easy to service.

Another object of this invention is to provide a roller rock bit embodying sets of inner cutters rotatably supported on a single angular pin supported intermediate its ends by a novel removable stud.

Another object of this invention is to provide a roller rock bit in which the several cutter supporting legs or shanks are integral parts of the u body. 4 l "o Another object of this invention is to provide a roller rock bit of the character mentioned in which the shafts or pins supporting the outer cutter bushings are subjected to little or no shear strain and, therefore, are not liable to fail when the tool is in operation. y

Another object of this invention is to provide a roller rock bit in which the removable parts are securely and dependably locked against loss and displacement when the tool is in operation and yet may be easily removed for replacement, etc.

Another object of this invention is to provide a rollerV rock bit embodying improved means for flushing the several roller cutters.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is'a central longitudinal detailed secf tional view of the bitprovided by this invention, being a view taken as indicated by line I-I on Fig. 2. Fig. 2 is a fragmentary vertical detailed sectional view taken substantially as indicated by line 2-2 on Fig. 3. Fig. 3 is a reduced side elevation of the blt and Fig. 4 is a fragmentary transverse detailedV sectional view taken as ln- The improved roller bit of the present invention -jinc1udes, generally, abody III, two sets of inner 'roller cutters II and I2, means I3 rotatably supporting the cutters II and I2, two outer cutters I4, means I5 rotatably mounting the outer cut- (Cl. Z55-71) ters I4, and means I6 for ushing the cutters II, I2 and I4.

The shank or body III is provided to carry the cutters and the various other parts of the tool. The body I0 is adapted to be connected with the 5 lower end of a well drilling string and is provided at its upper end with suitable connecting means. In the particular case illustrated a tapered screw threaded socket I I is provided in the upper end of the body III to receive the threaded pin I8 of a drill collar or the like. 'I'he body I0 is an integral member having a cylindrical upper part through which the socket Ilextends. The lower portion of the body I0 is preferably of enlarged diameter and is open at its lower end. Depending parts or wings are provided on the lower,end of the body I0 to carry the cutter mounting means I3 and I5. Legs or wings I9 project downwardly from the body Ill at diametrlcally opposite points. The wings I9 project downwardly and slightly outwardly. Raised or inwardly projecting parts are provided on the inner sides of the wings I9 adjacent their lower ends and present ,substantially vertical thrust surfaces 2li. A ilat downwardly facing shoulder f 2| is provided at the lower end of each thrust surface 2li.q The lower ends or wings I9 are preferably bevelled downwardly and inwardly as clearly illustrated in Fig. 2;

The invention includes wings 22 projecting downwardly and outwardly from the lower portion of the body I0 at points substantially 90 from the above described legs I9. Raised surfaces 23 are provided on the inner sides of the legs 22. The surfaces 23 are inclined down- 35 wardly and outwardly relative to the central longitudinal axis of the bit. Flat faces or shoulders 24 are provided on the lower ends of the wings 22 and are normal tothe thrust surfaces 23. The spaced legs I9 and 22 surround or define a relatively large socket-like space at the lower end of the body I0. An integral partition or wall 25 separates the socket I1 from the space or opening in the lower end of thc body I0. In accordance with the inventionl a web 26 depends from the wall 25. The web 26 is an integral part of the body Ill and lies in and adjacent the central vertical plane ol thi; body. The web 26 is relatively thin and its opposite side edges which oppose the wings 22 slope downwardly and outwardly. Inner wings 2l form integral continuations oi the web 26. The wings 21 are inclined downwardly and outwardly relative to the central vertical axis of thc tool and present raised thrust surfaces 28 which are spaced from and 55 parallel with the surfaces 23. Flat shoulders 29 occur on the lower ends of the wings 2l. The shoulders 29 are preferably normal to the thrust surfaces 8.

The cutters ll and I2 are rotatably supported in the open lower end of the body l0 to act on the inner portion of the bottom wall of the well bore. The inner cutters are arranged in sets or pairs each pair comprising a relatively small cutter II and a larger cutter l2. The cutters II and l2 are in the nature of roller cutters, the cutters I I being cylindrical cutters and the cutters i2 being frusto-conical cutters. The re1- atively small cutters Il havecentral longitudinal openings 30 and peripheral cutting teeth 3 I. The cutting teeth 3I may be straight and axial. lin the preferred construction the inner ends of the teeth 3| project beyond or overhang the inner ends of the cutters II. The opposite ends of the cutters II may be flat and normal. The frusto-conical inner cutters I2 have central longitudinal openings 32 and flat normal ends. Peripheral cutting teeth 33 are provided on the cutters l2. The teeth 33 may be straight and axial or may be spiralled if desired. The teeth 33 project beyond or overhang the large ends of the frusta-conical cutters I2. The cutters l2 are considerably larger than the cutters ll, their small ends being larger in diameter than the cutters il.

The means I3 operates to dependably support the sets of inner cutters I I and l2 for rotation about downwardly and outwardly inclined axes. The cutter mounting means I3 includes a substantially transverse shaft or pin 34. The pin 313 is angular having its major end portions inclined downwardly and outwardly. The intermediate portion 34a of the pin 34 is substantially horizontal. The opposite extremities 35 of the pin 34 are reduced in diameter. It is to be understood that the pin 34 may be cylindrical in transverse cross section. The pin 34 extends transversely between" the two opposite wings I 9 and its intermediate portion 34n is at the vertlcal center of the tool. Studs or screws 36 are passed inwardly through downwardly and outwardly inclined openings 3'I in the legs I9 and are threaded in openings 38 in the opposite ends of the pin I3 to connect the ends of the pin with the legs i9. The screws 36 have heads 36a countersunk. or recessed in the outer ends of the openings 31. The invention provides means for dependably securing the screws 36 against unthreading. Edge or corner portions 39 of the heads 36a are peened into notches in the outer sides of the legs I9 to lock the screws 36 against rotation and unthreading.

The invention provides means for supportingv the pin 34 intermediate its ends. A central vertical opening 40 is provided in the body web 26. The opening 40 extends downwardly from the socket II to the lower end of the web 26. A downwardly facing annular shoulder 4I is provided on the wall of the, opening 40. The cutter mounting means I3 includes a stud 42 arranged longitudinally in the opening 40. The stud 42 has a shoulder 43 adapted to bear upwardly against the shoulder 4 I. A transverse opening 44 is provided in the lower portion of the'stud 42 and receives the straight intermediate portion 34a of the pin 34. A lock pin 45 ls arranged through transverse openings in the pin 34 and the stud 42 to secure the pin to the stud. The

supporting lstud 42 projects upwardly into the socket II and a nut 46 is threaded on its proanimee jecting upper end. A washer 41 is provided under the nut 46. The nut 46 may be locked in place by a cotter key, or the like. The nut 46 urges the stud 42 upwardly so that its shoulder 43 is clamped against the shoulder 4I. The stud 42 serves to rigidly and dependably support the pin 34 between its ends. Thus the pin 3,4 is supported at its opposite ends and at its middle portion.

The cutters II are rotatable on the pin 34 adjacent the opposite sides of the stud 42. In practice the inner cutters II may be directly rotatably supported on the pin 34. The stud 42 is preferably provided with downwardly convergent thrust surfaces 48 against which the inner ends of the cutters Il may bear. The projecting inner ends of the teeth 3| overhang a substantial portion of the lower end of the stud 42 to prevent the engagement of the earth formation with the stud. The teeth 3l projecting inwardly below the end of the stud 42 act on the earth formation immediately adjacent the center of the well bore. The cutters I2 are rotatably supported on the pin 34 between the cutters ll and the wings i9. Roller bearings 49 may be provided to rotatably support the cutters I2 on the pin 34. 'I'hrust washers 50 are interposed between the outer ends of the cutters I2 and the wings I9. The washers 50 are arranged on the reduced end portions 35 of the pin 34 and their inner surfaces are engaged by the outer ends of the cutters I2. The outer sides of the washers 5D cooperate with the thrust surfaces 20. Extensions or lugs 5I are provided on the washers 50 and cooperate with the shoulders ZI to hold the washers against rotation and to transmit the operating thrusts directly to the wings I9. The lower ends of the washers 50 and their lugs 5I may be bevelled oiffiush with the lower ends of the wings I9.

In assembling the inner cuttersv II and I2 on the body I0, the pin 34 is first entered in the opening 44 and is secured to the stud 42 by the pin 45. The cutters II and I2 are then properly arranged on the pin 34 and the washers 50 are placed on the end portions 35 of the pin. The Washers 50 may be force-fitted or press tted on the end portions 35 to retain the cutters II and I2 on the pin 34 and thus facilitate the handling of the assembly. The stud 42 is then passed upwardly through the opening 40 at which time the lugs 5I are brought against the shoulders 2| The screws 36 are then threaded in place and the nut 46 is threaded on the stud 42 to secure the cutter supporting assembly to the body l0.

The outer cutters I4 are in the nature of frusto-conical roller cutters. Each cutter I4 has a .central longitudinal opening 52. The opposite ends of the cutters i4 are preferably flat and normal. Suitable peripheral cutting teeth 53 are provided on the outer cutters I4. 'I'he teeth 53 may be straight or spiralled, as desired. The outer corners ofthe teeth 53 are preferably bevelled off while the inner ends of the teeth 53 preferably overhang or project inwardly from the inner ends of the cutters I4.

The means I5 rotatably support the inner cutters I4 between the opposed Wings 22 and 21. The cutter supporting means I5 include bushings 54. The bushings 54 are arranged between the I adjacent opposed wings 22 and 2`I and are inclined downwardly and inwardly, having their longitudinal axes normal to the surfaces 23 and 28. The cutters I4 may be rotatably supported on the bushings 54 through suitable roller bearings 55. The cutters I4 lare arranged with their large ends outermost and being rotatable about inclined axes the bcvelled outer ends of their teeth 53 are substantially vertical when the teeth come into engagement with the formation. Thrust flanges 56 are provided on the inner ends of the bushings 54. The flanges 56 constitute thrust i I -washers for transmitting operating thrusts from the inner ends of the cutters I4 to the wings 21. The outer sides of the flanges 55 are adapted to bear on the surfaces 28 while the inner ends of the cutters I4 and the bearings 55 bear on the inner surfaces of the flanges. Each flange 55 has a lug 51 cooperating with a shoulder 29 to prevent rotation of its bushing 54 and to transmit upward thrusts directly to the wings 21. The outer end portions 54u of the bushings 54 are reduced `in diameter and thrust washers 58 are provided on the reduced portions 54a. The washers 58 may be pressed or force-fitted on the reduced bushing portions 54EL to retain the cutters I4 and the roller bearings 55 on the bushings to facilitate the handling and transporting of the cutter assemblies. The washers 58 are engageable by the outer ends of the rollers 55 and the cutters I4 and bear on the surfaces 23 to transmit the end thrusts directly to the body wings 22. Extensions or lugs B are provided on the washers 5B and cooperate with the shoulders 24 to prevent rotation of the washers and to transmit upward thrusts to the wings 22. The lower outer corners of the washers 58 and their lugs 59 are bevelled off so that they do not contact the side wall ofthe well bore.

The cutter supporting means I5. includes pins 5I! for holding the bushings 54 in place and for tying together the adjacent legs 22 and 21. Aligned downwardly and inwardly inclined openings I and 6I are provided in the legs 21 and 22 respectively. The pins 60 are passed outwardly through the openings 6I in the legs 21 and are threaded in the openings (iln in the legs 22. Suitable heads 62 are provided on the inner ends of the pins 60 and are countersunk in the inner ends of the openings 6l. Means are provided to prevent rotation and unthreading of the pins 60. 'I'he outer end parts of the pins 60 are reduced and unthreaded. Extreme end or corner portions 53 of the pins 60 are peened into notches vin the legs 22 to prevent unthreading of the pins. 'I'he cutters I4 rotatably mounted as just described project downwardly beyond the lower ends of the legs 22 and 21 to act on the outer portion of the bottom wall of the well bore and to cut the well bore to gauge. The inclination of the cutters I4 is such that the lower edges of their teeth 53 are `inclined downwardly and inwardly as the teeth tion and the lower ends of the legs 21 and the washers 56 do not come into contact with the earth formation.

The means I6 for flushing the cutters II, I2 and I4 provides for the full effective flushing of the several cutters. The ushing means I6 includes'or provides a plurality of circumferentially spaced openings in the ybody wall 25. The openings 10 extend downwardly from the bottom oi the socketr I1 to the lower Surface of the wall 25. The openings 10 are cylindrical and each has an upwardly facing annular shoulder 1I adjacent its lower end. The longitudinal axes of the openings 10 are inclined downwardly and outwardly.

kIn accordance with the invention the openings 10 are positioned so that one opening is above each outer cutter I4 and so that an opening 10 is above each pair of inner cutters II and I2.

The means I5 further includes ow nipples or chokes 12 arranged in the openings 10. The chokes 12 are cylindrical members entered in the openings 10 from their upper ends. The chokes 12 closely'flt the openings 1li and their lower ends bear on the shoulders 1I. Each choke 12 has a longitudinal fluid discharge opening 13. The openings 13 are cylindrical at their upper ends and are transversely elongated at their lower ends. The walls of the openings 13 are smooth and gradually rounded to provide for the ready major transverse axes substantially vertically aligned with the axes of the cutters I4 and the axes of rotation of the cutters II and I2. Thus the uid discharge openings 13 direct transversely elongated streams of circulation fluid against the cutters, which streams extend throughout the lengths of the cutters to effect the full flushing of the cutters.

The washer 41 constitutes a means for holding' the chokes 12 in place. The washer 41 contacts the inclined upper surfaces of the chokes 12 adjacent their peripheral edges to hold the chokes down and prevent their rotation. The lower ends of the body socket I1 is open and receives the circulation fluid from the well drilling string S. This circulation fluid passes from the socket I1 through the openings 13 at an increased velocity. The openings 13 direct the circulation uid downwardly against the teeth of the cutters II, I2 and Ill to clear them of mud and cuttings.

It is believed that the operation ofthe improved roller bit provided by this invention will bc readily apparent from the foregoing detailed description. In operation the tool is connected with the lower end of the drilling string S which is rotated and fed downwardly. During rotation of the string S the cutters I I, I2 and I4 act or roll on the formation at the bottom of the well bore to crush or cut away th'e same. The cutters II and I2 being rotatable about downwardly and outwardly inclined axes act on the upper surface y of a central conicalmound on the bottom wall of the well bore. The cutters Il being smaller in diameter than the cutters I2 provide a step or shoulder on this conical mound. The inner cutters II and I2 acting on the stepped conical mound in the center of the well bore act to center and stabilize the rotating bit. It will be noted that the cutters II and I2 areadapted to engage substantially the entire inner portion of the well bore. The outer cutters I4 pursue an annular course surrounding and overlapping the course of the cutters I2 to cut away the outer portion of the well bore. The cutters I4 also operate to engage the side wall of the well to cut the well to gauge. Circulation fluid is pumped downwardly through the string S and discharges from the' choke openings 13. As described above, the uid is discharged from the openings 13 in inclined transversely elongated streams which flush the cutters II, I2 and I4 throughout their lengths.

by the stud 42. The screws 35 securing the ends 75 70 j. in its upper ,end and an opening extending downof the pin 36 to the legs i9 tie the legs to the pin and lend rigidity to the assembly. The pins 6U hold the bushings 54 in their proper inclined positions and serve to tie the legs 22 to the legs 21. The bushings 54 and the washers 58 receive the thrusts from the cutters i4 so that the pins 60 are subjected to very little Wear and pressure. The various Wear receiving parts of the tool may be easily and quickly replaced to recondition the tool for further use.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims:

Having described my invention, I claim:

l. A roller bit including, a body having wings projecting from its lower end, a shaft extending between the wings and having oppositely inclined end portions, means securing the ends of the` shaft to the wings, a depending stud removably carried by the body and having an opening carrying the intermediate portion of the shaft, and roller cutters on the inclined portions of the shaft.

2. A roller bit including, a body having wings projecting from its lower end, a shaft extending between the wings and having oppositely inclined end portions, screws securing the ends of the shaft to the wings, a depending stud on the body having an opening carrying the intermediate portion of the shaft and cutters rotatable on the inclined portions of the shaft.

3. A roller bit including, a body having wings projecting from its lower end, a shaft extending between the wings and having oppositely inclined end portions, means securing the ends of the shaft to the wings, a removable stud depending from the body and having an opening carrying the intermediate portion of the shaft, downwardly convergent bearing surfaces on the stud 'at the ends of the opening, and roller cutters rotatable on the inclined portions of the shaft and bearing on said surfaces.

4. A roller bit including, a body, wings projecting from the lower end of the body and having substantially vertical inner sides, a shaft extending between the wings and having oppositely inclined end portions, means connecting the ends of the shaft to the Wings, means supporting the shaft intermediate its ends, roller cutters rotatable on said inclined portions of the shaft, and thrust washers between the inner sides of the legs and the ends of the adjacent cutters, each washer having convergent sides, one bearing on the inner side of a leg, the other .engageable by a cutter.

5. A roller bit including, a body having wings projecting from its lower end, a shaft extending between the wings andgiaving oppositely inclined end portions, means securing the ends of the shaft to the Wings, a depending stud removably carried by the body and having an opening carrying the intermediate portion of the shaft, a lock pin arranged through transverse openings in the stud and shaft, and roller cutters on the inclined portions of the shaft.

6. A roller bit including, a body having a socket ward from 'the socket, legs depending from the .body, a stud arranged in said opening and projecting from-the lower end of the body, the proarranca jecting portion of the stud having a horizontal opening, a pin having a horizontal portion. carried in said horizontal opening and downwardly and outwardly inclined portions extending toward the legs, means tying the ends of the pin to the legs, and roller cutters rotatable on the inclined portions of the pin.

7.' A roller bit including, a body having wings n projecting from its lower end, a shaft extending between the wings and having oppositely inclined end portions, means securing the ends of the shaft to the wings, a depending stud removably carried by the body and having an opening carrying the intermediate portion of the shaft, and roller cutters on the inclined portion of the shaft having cutting teeth extending inwardly at the lower end of the stud.

8. A well bit including, a body having diametrically opposite depending wings, a web on. the body projecting downwardly between the wings, inner wings on the web spaced from and opposing the iirst mentioned wings, roller cutters supported between the adjacent opposed wings for rotation about inclined axes, parts integral with the body and projecting downwardly from the body at points spaced from the first mentioned wings, there being an opening in the web, a removable stud carried in the opening, a transverse pin l supported between its ends by the stud, means tying the ends of the pin to the said parts, and roller cutters on the pin.

9. A well bit including, a body having diametrically opposite depending wings, a web on the body projecting downwardly between the wings, inner wings on the web spaced from and opposing the first mentioned wings, roller cutters supported between the adjacent opposed wings for rotation about inclined axes, parts projecting downwardly from the body at points spaced from the first mentioned wings, there being an opening in the web, a removable stud carried 1n the opening, the stud having a transverse opening, a transverse pin having its intermediatey portion carried in the opening of the stud and being inclined downwardly and outwardly from the stud, cutters rotatable on the pin, and means tying ends of the pin to the said parts.

10. A well bit including, a body having a uid chamber and spaced openings extending from said chamber to an external surface, roller cutters rotatably supported by the body, chokes in said openings having transversely elongate openings discharging correspondingly shaped streams against the cutters, and a single means retaining @the several said chokes in the openings.

11. A well bit including, a body having a fluid chamber and spaced openings extending from said chamber to an external surface, roller cutters, means supporting the cutters on the body including, a part projecting into said chamber, chokes in said openings discharging streams of uid against the cutters, and a member on said part retaining the chokes in the openings.

12. A well bit including, a body having a fluid chamber and spaced openings extending from said chamber to an external surface, roller cutters, means supporting the cutters on the body including, a part projecting into said chamber, chokes in said openings discharging streams of fluid against the cutters, and a retaining nut on said partl securing the same to the body. and holding the chokes in the openings.

ALFRED c. CA'I'LAND. 

